Regional cardiac function assessment in 4D CT: comparison between SQUEEZ and ejection fraction.

Recent advances in computed tomography (CT) imaging technology allow fine anatomical structures such as endocardial trabeculae to be resolved. We have developed a method to detect and track such features on the endocardium to extract a measure that reflects local myocardial contraction with minimal human operator interaction. The relative motion of these surface features were used to represent the local contraction of the endocardial surface with a metric we termed "stretch quantifier of endocardial engraved zones" (SQUEEZ). The results were compared against CT function analysis software available through the scanner vendor. SQUEEZ showed significant difference between infarct and remote regions (p<0.0001) as verified by delayed enhanced magnetic resonance imaging. The vendor software showed inferior spatial resolution and stair-step artifacts in regional function maps.